Although evaluations of the ONDCP-sponsored drug prevention campaign have found limited evidence of campaign impact on drug use, it is reasonable to propose that different analyses may find that the campaign did have an impact-but that the messages did not impact all individuals in the same way. Most researchers treat non-users as a homogeneous group. By longitudinally studying change between non-users and non-using intenders, greater insight into the change process will be attained. Inspecting similar patterns between non-using intenders and users also will facilitate understanding. Taking a preventive focus, the proposed project draws on research indicating that drug use is a purposeful behavior. Adolescence is a time of physical, psychosocial, and environmental change. As part of this process adolescents come to see drug use as an act that will hinder or facilitate adjustment to their changing environment. To influence adolescents not to use drugs, we must understand the environmental and interpersonal changes that lead adolescents to associate drug use with potentially positive outcomes. Of particular interest is the delineation of predictive models of drug use and intent that incorporate variables amenable to change via preventive interventions. An equally important goal is to understand how non-users, non-using intenders, and users differentially notice, and respond to, anti-drug messages. There is a long-standing body of research demonstrating that individuals will differentially attend to and process information depending on how relevant that information is perceived to be. It follows that adolescents will attend to and process information about the benefits and harms of marijuana differently depending what information they see as relevant. The totality of this proposed project will provide a new roadmap for future intervention efforts. Relevance: The proposed project will provide new insight into the impact of the ONDCP-sponsored drug prevention campaign, via cross-sectional and longitudinal analyses on the differential behavior and response patterns of non-users, non-using intenders, and users of marijuana-a division virtually non-existent in the current literature. Knowledge will also be gained by considering the potentially purposive nature of drug use and exploring how non-users, non-using intenders, and users of marijuana differentially recall and respond to anti-drug information.